But she's definitely been made worse. In some of the comics, she has had arcs (here and there; they can be rare) with real, actual depth. Some of the justifications for her Suicide Squad costumes... 'We want to show that she's owning her sexuality.' I mean, OK. I kind of get that? But at the same time... Not many women (if any) are gonna go to the theater and think 'girl power' with those outfits. They're going to sigh about yet more fanservice.
If she's been made worse, that's another issue. I'm merely disputing that she was smartly written in B:TAS, or was calculated to be so. It's really not until the second and third seasons that Harley gets out on her own, and, even then, her relationship with Mr. J is less about abuse and more from sheer crazy.